The present invention relates to improvements in a drive mounting for an elevator scraper, and more particularly, to such a drive mounting having means for preventing axial misalignment.
Elevator scrapers typically contain a large rectangular frame member mounted on a vehicle, with the frame member supporting all of the elevator structure including the drive unit therefor. Such drive mountings generally comprise a main drive shaft mounted on the frame at each side thereof, with main drive shaft having a pair of drive sprockets adapted to drive a pair of endless chains. The chains are supported on suitable idlers also carried on the frame and comprise a plurality of transverse flights for conveying dirt and like material into the bowl of the scraper. The main drive shaft is provided with a motor and gear reduction unit suitable for driving said shaft, and in the present invention, the motor and gear unit are preferably carried at one end of the shaft externally of the main drive.
Such elevator scraper drive systems have been in use for a long time and are eminently satisfactory. However, certain problems have arisen which contribute to the wear of the device and facility of use thereof. The present invention is directed toward improvements in solving these problems.
Specifically, when the drive structure is mounted onto the frame, the manufacturing tolerances of the frame frequently cause one end of the drive structure to be axially misaligned with the other. Consequently, mountings should be provided to accommodate for such misalignment between the opposite ends of the drive structure to prevent the creation on undue stresses in the various components thereof, because such stresses may eventually cause a failure and reduce the useful life of the structure. In addition, stresses are caused in the elevator frame during use of the scraper such as when rocks or the like are struck, because such forces tend to temporarily affect slight changes in the frame configuration. Due to the large size of the frame, very slight changes in alignment and stress forces are sufficient to affect these alignment problems. Accordingly, means should be provided to protect the mounting bearing structures. However, it is also important that the structure be strong and maintain rigidity in order to operate effectively.
Another problem which has been encountered in elevator scrapers resides in the fact that the drive motor for the scraper frequently needs more maintenance and/or replacement than the other drive elements. When such motor maintenance is conducted, it has heretofore been necessary to provide support for the extremely heavy elevator drive components externally of the machine. In other words, the motor and associated gearing could not be removed without disconnecting a support for the main drive shaft on which all of the other elevator drive elements are supported.